As from January 2013 the new Energy Efficiency Design Index (EEDI) regulations as amended in MARPOL Annex VI are being enforced, aiming at a reduction of CO2 emissions from ships. For each new ship this index is calculated by dividing emissions by the benefit to society, expressed as transport capacity times speed of the vessel. In comparison with other ship types, especially the smaller general cargo ships have a poor correlation of EEDI values with deadweight (DWT). The objective of this research is to determine the cause of this scatter and see if additional correction factors would give a fairer inclusion of these ships within the EEDI regulatory framework. It was found by means of regression analysis that the volumetric Froude number and block coefficient explained a large part of the variation in the EEDI values. Three correction factors have been developed to compensate vessels for effects of differences in operation profile, additional class notations and installed loading gear. The factors have been accepted at IMO's MEPC 65 to be included in the guidelines.